Union Pacific Railroad steam locomotive number 7866 at Tacoma, Washington, in 1940. UP 7866 with a westbound extra freight at Sixth Avenue station in Tacoma in 1940. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight train.

Union Pacific Railroad steam locomotive number 7868 at Tacoma, Washington on January 22, 1936. UP 7868 with a passenger train at Tacoma in 1936. Photo by Herman Hunt, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, passenger train.

Union Pacific Railroad steam locomotive number 7869 at Tacoma, Washington on February 10, 1936. UP 7869 with a passenger train at Tacoma in 1936. Photo by Herman Hunt, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, passenger train.

Union Pacific Railroad steam locomotive number 9039, undated. UP 9039, a 4-12-2 on a freight at track speed. Photo by Marge Wilson, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, freight train.

United States Navy 0-4-0T steam locomotive number 6992 parked at Pasco, Washington, on September 24, 1948. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, switching locomotive.

Unknown Climax steam locomotive with log train, circa 1930. Photo from J.M. Fredrickson Collection. Other Subject Classes: steam locomotive, logging locomotive, railroad crew.

Unknown Shay steam locomotive, circa 1946. Photo from J.M. Fredrickson Collection. Other Subject Classes: steam locomotive

Unknown steam locomotive number 14 a 2-8-0 steam locomotive, on static display at Custer, South Dakota on September 1, 1972. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, display.

Unidentified 4-4-0 steam locomotive number 67 with "Eastern" marking on the tender at a depot platform, circa 1890. Photo from J.M. Fredrickson Collection. Other Subject Classes: steam locomotive, passenger train.